Chemically Talking, this molecule is "halfway" in between Sorbitan Oleate and Sorbitan Trioleate, that means that it is also an attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the unsaturated fatty acid Oleic Acid, but within a ratio of 2:3 for this reason the "Sesqui" section inside the molecule's title. When trying to find c